The present invention is directed to cantilever bicycle brake devices.
Bicycles capable of off-road travel, such as MTBs (mountain bikes) are equipped with cantilever brake devices in order to provide strong braking force. Cantilever brake devices straddle both sides of the bicycle rim to provide braking action, and are generally equipped with a pair of left and right brake links, brake shoes attached to the brake links, and coil springs which energize the brake links towards the brake release position. The brake links are rotatably supported in cantilever fashion by mounting pins that project from pedestals provided to the front fork or rear fork (seat stay) of the bicycle. Each coil spring is disposed within the rotatably supported member of a brake link, with one end of the spring protruding the rotatably supported member and engaged by any one of three engagement holes provided to the pedestal. These three engagement holes are disposed at positions located an equal radius from the center of the mounting pin. By changing the position at which the coil spring is engaged by the pedestal, the spring power (force towards the brake release position) can be varied between three levels.
With the conventional cantilever brake device described above, inserting the coil spring into an engagement hole presents no particular problem when it is possible to rotate the brake link in order to place the one end of the coil spring at a position such that it can be engaged by the engagement hole. However, when changing the spring force or mounting the brakes, where the wheel interferes with the brake shoes so that the brake links cannot be rotated inward very far, where the fork interferes with the brake shoes so that the brake links cannot be rotated outward very far, and in similar cases where rotation by the brake links is restricted, it is sometimes not possible to readily position the end of the coil spring within the coil spring with needle-nose pliers or a similar tool, or to perform some similar complicated procedure in order to position the spring end within the desired engagement hole. Thus, the end of the coil spring can not be easily positioned within the engagement hole.